1. Field of the Invention
The present invention relates to a sunless tanning composition and its use in sunless tanning products. More particularly, the present invention relates to a method of sunless tanning that employs the sunless tanning composition according to the present invention and provides fast development of uniform, more intense, long-lasting and natural looking tan with more predictable, i.e., customized, color characteristics.
2. Description of the Related Art
U.S. Pat. Nos. 5,645,822 and 5,750,092 to Schering-Plough and European Patent Application No. 0 547 864 A1 describe attempts to provide sunless tanning. However, these and other approaches described in the art have certain drawbacks.
Products that are currently used for sunless tanning of the skin are based on the reaction of an active chemical present in the product with the skin amino acids. Such chemicals are well known and include compounds having an aldehyde group, or compounds having a ketone group, such as, for example, Dihydroacetone.
As an example, DHA gives skin a brownish color by reacting with the amino acids present in the sebum and stratum corneum by a known mechanism, namely the Maillard reaction.
Further, distribution and nature of the amino acids is not uniform on the surface of the skin and because of that the intensity and shade of the color obtained may vary from one place to another on the treated skin thereby causing the skin to have an unnatural look.
Further still, the duration of time required for development of skin color may be too long, which can lead to a decrease in the concentration of DHA on the surface of skin due to sweating or as a result of contact with clothing thereby staining the clothing and resulting in an uneven color development on the skin.
Thus, it is very desirable to obtain a uniform and natural looking sunless tan over all skin surfaces that are treated with a sunless tanning composition that can develop faster and last longer than formulations known in the art.
Thus, there is a need in consumer products and cosmetic industry for formulations that can enhance the effectiveness of the active ingredient used in sunless tanning and deliver increased performance characteristics and eliminate the need for exposure to damaging rays of the sun for tanning.